This is a graphics glitch that takes the form of a blue bar that obfuscates the bottom part of the screen, therefore covering the UI. It happens whenever I move my characters, but stops happening when they stop moving. I have tried disabling AA, disabling Vsync, windowed mode, and updating graphics drivers.
You can replicate this bug by moving your character(s). This bug only happens when they are moving, and stops when they are still.
Screenshots:
http://cloud-4.steamusercontent.com/ugc/528385406420959411/3879FC4D11B3F2A827E3A2448FEFA14B0714B916/
http://cloud-4.steamusercontent.com/ugc/528385406420958459/69B5759A03E556AECDDAE6836AA6603726A0AC4A/
Dropbox file:
https://www.dropbox.com/s/7137em9b0w0p74h/Blue%20bar%20UI%20glitch.7z?dl=0